Wild Ideas: The pitter patter of not-so-tiny feet

I had lots of different species of rodents as pets and harbor no ill will against them generally, but living with rodents loose in the house is just not a healthy or practical situation for several reasons.

For one thing, rodents are compelled to gnaw, since their teeth don’t stop growing, and can target wood and electrical wires, as well as chewing up softer materials to line their nests. I was reorganizing my coat closet recently and found that a beautiful wool scarf my mother had given me had huge chunks missing, likely taken by some of the 50 or more house mice that infested my house last winter.

Alan Cressler via Wikimedia

While Virginia’s native Allegheny woodrat (seen here with its young) looks similar to the nonnative brown rat, the tails differ: the woodrat’s is covered with fur, while the brown rat’s is bare and scaly.

Another reason for not having rodents loose in the house is that pretty much all species can carry parasites or diseases that can be transmitted to humans. I got really tired of cleaning mouse poop off the kitchen counters and out of cabinets and drawers last year.

As November approached this year, I waited in trepidation for the pitter patter of little feet in my attic once more. It usually takes a while for the incoming mice to get inside my living space, but in the meantime, they breed in the attic and walls. The pitter patter did come, but my first thought was that, if this was from a mouse, it would be the sumo wrestler of mousedom.

If not a mouse, what could it be? I ruled out gray squirrels and flying squirrels for various reasons. That left me with my least-desired option: rats. Rats have had a complicated history with humans, running from plague carriers to medical-research subjects to pets.

While rats are tidier in their toilet habits than mice — depositing their poop in one location — they are still potential disease vectors. The Black Death in the Middle Ages was believed to be caused by a bacterium carried in fleas that infested the black or house rat (Rattus rattus), in the Muridae rodent family, although another species in the family, the brown rat (Rattus norvegicus) or Norway rat, was first suspected. While black rats are not common in the U.S., brown rats are, from cities to rural areas.

I finally got the chance to see my rodent house guest last week, albeit briefly. Coming home late on a rainy night, I had only a keychain flashlight to help illuminate the path to my front porch. Just as I started up the steps, a rat that was at least a foot long (including the tail) streaked in front of me, scaled the sheer wall of my house faster than I could say “Spiderman” and disappeared into the attic through a hole next to the chimney. I didn’t get a close enough look to be sure about species, but its behavior indicates it’s more likely in the Cricetidae rodent family — our native Allegheny woodrat (Neotoma magister).

Woodrats are generally shyer of humans than brown rats. When they do nest in our structures, they generally pick abandoned ones or quieter areas in inhabited ones, such as attics. They also don’t colonize and are instead are quite belligerent with others of their kind that invade their territory.

The Allegheny woodrat looks a lot like the brown rat. Both are about the same size — 12 to 18 inches long (the tail making up about half the length) and about 12 to 13 ounces — and both also have gray, brown or grayish brown fur covering the top of their bodies, with white undersides. The biggest difference in appearance between the two species is the tail: the woodrat’s is covered in fur, while that of the brown rat, like most Murids, is snakelike — bare and scaly.

Woodrats’ behavior differs from Murids in interesting ways. For one thing, they build piles of sticks and trash called “middens” near their nests. Primarily vegetarian, according to the International Union for Conservation of Nature (IUCN), the Allegheny woodrat caches nuts, seeds, berries, mushrooms and cuttings of vegetation in these storage locations.

Also known as pack rats or trade rats, woodrats also cache nonfood items. Nails, coins, bits of tin, colored glass, china, bleach bones and skulls, rags, and even eyeglasses and false teeth have been found in Allegheny woodrat nests, according to the Virginia Fish and Wildlife Information Service (VaFWIS). “The function of this compulsive collecting is unknown,” says IUCN.

Among several species of woodrats in the U.S., the Allegheny is a “microhabitat specialist” that depends on rocky areas for its habitat, according to IUCN, and ranges through most of the central Appalachians. It is found in most Virginia counties from the eastern slope of the Blue Ridge Mountains to the West Virginia border, including Rappahannock, according to VaFWIS.

While stable in Virginia, populations of the Allegheny woodrat are generally declining in the northeast and are already extirpated from Connecticut, Massachusetts, New York and parts of Pennsylvania, New Jersey and Maryland. IUCN now lists this species as being on the first rung of the ladder to extinction — “near threatened.” With a population decline of almost 30 percent, it is close to qualifying for the next rung, “vulnerable.” The reason for its decline is “not well understood,” says IUCN.

Before I moved into my current house, woodrats had occupied a now-demolished shed in the woods behind it, according to my landlords. Knowing that these rodents did live nearby and hearing what sounds like only one animal in my attic, I’m pretty sure the one I saw was a woodrat. Assuming it is, I have no desire to help it toward extinction. It has an important place in the food web, being preyed upon by many predators and spreading plant seeds around during its foraging and caching activities.

I’ve talked to my landlord and, once the recent icy weather has abated, the plan is to put a live trap in the attic to catch the rodent. If it is a woodrat, we’ll release it near the remains of the shed, where it should be able to find shelter. My landlord will then cover the hole to the attic with metal, since woodrats can chew through pretty much any other material. It should have a pretty good chance of surviving outside as long as it is still in its own territory and has other shelter available.

Writer, editor, photographer, and passionate nature conservationist living in Rappahannock County, in the Blue Ridge Mountains of Virginia. Two favorite quotes: By E.O. Wilson, who coined the term "biodiversity," "Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction”; by Douglas Adams, “I love deadlines. I love the whooshing sound they make as they pass by.”

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